Analysis of the etiology and pathogenesis of gastric cancer

The causes of gastric cancer are divided into internal factors and external factors. Their combined effects induce and cause endocrine system abnormalities and long-term low immune function, or abnormal cells escape the body's immune surveillance for some unknown reason, eventually developing into gastric cancer cells whose growth cannot be controlled by the body, thus forming a carcinogenic process.

Normal human gastric mucosal epithelial cells are continuously divided and differentiated by stem cells and are controlled by the body. Stem cells have various oncogenes and tumor suppressor genes. In most cases, oncogene characteristics are not expressed, carcinogens are not formed, and they cannot develop into gastric cancer cells. However, oncogenes with a family history of gastric cancer are more likely to be expressed, which is a genetic factor. In addition to internal factors such as heredity, there are many external carcinogenic factors, such as the various non-genetic factors faced by the above-mentioned high-risk groups, which can also directly induce or long-term damage to the gastric mucosal barrier, making it easier for carcinogens to induce stem cell oncogene expression or gene mutations to produce carcinogens, so that the newly immature primitive cells cannot differentiate into gastric mucosal epithelial cells with normal functions, but become various abnormal cells with poor differentiation and uncontrolled growth.

The cancer process can take decades. Once cancer cells are formed and resist the body's immune surveillance, they will explode and grow into gastric cancer lesions visible to the naked eye. Local cancer lesions continue to grow, occupying the space of normal gastric cells, thus affecting the normal function of the stomach, and even directly infiltrating into adjacent tissues and organs and continuing to grow. As cancer cells grow wildly and uncontrollably in various parts of the body and continuously rob normal cells of nutrients, normal tissues and organs fail due to extreme malnutrition, eventually leading to the death of gastric cancer patients.